The Perseid meteorite showers return on Monday and you may not have realized it, but there are business links with these rocks from the sky.

Here's six things you might not have known about meteorites.

They brought us (some) gold.

Left to its own devices, Earth wouldn't have much of any iron-loving precious metals – gold, platinum, rare earth elements – at its surface. In fact, just about all of earth's original gold and platinum are all locked up in the earth's core, where they sank when the earth was first forming. The only reason we have much precious metal on the earth's surface is because meteorites deposited it from space.

They are different from meteors.

A meteor is the light given off by a piece of space rock as it travels through the Earth's atmosphere. A meteoroid is the actual space rock if it's less than a meter in size. If the space rock is bigger than a meter, it's an asteroid. A meteorite is a space rock that isn't completely burned up on entry and actually makes it to the ground. Read more here.

They are super expensive.

Fragments of the Chelyabinsk meteorite that exploded over western Russia last year sell online for $30 a gram (As of now, gold sells for $40 a gram). Other meteorites can sell for $1,500 a gram.

They can come from other planets.

If a comet or asteroid slams into another planet, it can knock chunks of that planet off and back into space. Sometimes those chunks can fall to Earth, becoming meteorites. That's why we have meteorites from the moon and Mars.

They may hold the key to space mining.

"The Holy Grail of asteroid science is if you can can relate a particular type of meteorite to a parent asteroid in space," says Donald Yeomans, who runs NASA's Near Earth Object Program Office at the Jet Propulsion Laboratory.

If you can understand what types of meteorites contain what types of elements — whether metals or hydrated minerals — and you can figure out their signature, you can use that as a key to understand what an asteroid contains from a distance. That way you can figure out what of value is in an asteroid you're thinking about mining without having to visit it.

They have organic material in them.

Meteorites can even have several percent by weight of organic material— Amino acids, nucleic acids, carboxylic acids.

"How that organic material formed is a big question," says Conel Alexander, a cosmochemist at the Carnegie Institution for Science. "Some people think it formed in interstellar space before the solar system formed. Others think it was created in the disc of gas and dust from which the planets were forming. It raises the intriguing possibility that all solar systems would be seeded with prebiotic soup from which life emerged."